A preliminary study to evaluate the exposure of human fetus to heavy metals in the umbilical cord blood in Syria

Abstract The environmental situation in Syria needs a comprehensive assessment, especially in light of the conditions it has been experiencing for thirteen years, which have exacerbated pollution with heavy metals (HM) in various regions, including the coastal one. This preliminary and first survey in Syria aims to evaluate the exposure of human fetus in the population to HM by measuring the toxic metals spread in the coastal environment in the umbilical cord blood (UCB), which are lead (Pb), mercury (Hg), cadmium (Cd), arsenic (As), chromium (Cr) and nickel (Ni). The study was conducted between May 2022 and April 2023 among healthy newborns of the National Maternity Hospital in the Mediterranean coastal city of Tartous. This study adopted the official method of the American Association for Analytical Chemistry (AOAC, 2002) in collecting, preserving and processing UCB samples, and the heavy metals were measured using an Atomic Absorption Spectrometer. The statistical study was carried out using SPSS Statistics 23.0 (Statistical Package for Social Sciences). The lower and upper limits for the concentrations of the studied elements in UCB range between: Pb (6.18-17.60µg/L), Hg (1.05-7.62µg/L), Cd (0.01-0.67µg/L), As (0.30-5.70µg/L), Cr (0.02-0.43µg/L), Ni (0.01-0.94µg/L). The concentrations of all HM measured in UCB are below the recommended international reference limits. This paper represents the first step in studying the assessment of fetal exposure to HM in our region. The current and future studies aim to expand the study area to include all of Syria, in addition to linking laboratory levels of HM with various sources of exposure and pregnancy outcomes observed at birth.